Integral treatment of coupled heat and mass transfer by natural convection from a cylinder in porous media

This paper deals with the study of the buoyancy induced heat and mass transfer from a slender body of revolution embedded in a saturated porous medium. The study has reported the important case of a cylinder with linear temperature and concentration distributions. The governing parameters for the problem under study are buoyancy ratio (N) and Lewis number (Le). The numerical values of local Nusselt and local Sherwood numbers have also been computed for a wide range of N and Le. The results pertaining to the variations of local Nusselt number, local Sherwood number, N and Le with one another have been studied graphically, and it has been concluded that the local Nusselt number decreases while the local Sherwood number increases along with N>0 for increasing Lewis number. The local Nusselt number decreases while the local Sherwood number increases along with Le for positive values of N. Also the boundary layer thickness ratio decreases along with Le for N>=0. In this study, an integral method of Von-Karman type has been used in order to obtain mathematical expressions for local Nusselt and local Sherwood numbers. (C) 2008 Elsevier Ltd. All rights reserved.